This invention is directed to lifting tools or mechanisms in general and, more particularly, to apparatus for lifting heavy, bulky objects of somewhat irregular configuration. The apparatus is ideally suited to lifting fluid control apparatus such as control valves, gate valves, ball valves and flanged pipe joints. It has particular usage with water control valves and hydrants of the types generally installed in municipalities. Mechanisms of this type are usually so heavy that they cannot be lifted by a person and, in many instances, two or three strong men cannot lift them.
Many gate valves and at least the shoe portion of fire hydrants are located underground. Thus, the valve or hydrant must be lifted, lowered into a pre-dug hole or trench in a precise manner, which is called hydrant setting, then it is connected to a water supply pipe. This requires not only moving the valve to its ultimate destination where it will be joined to a supply pipe but, generally, a number of instances of vertical lifting and lowering are encountered in the process.
Before such apparatus is finally connected to the water system, it must be moved from the manufacturer's assembly line or location to a storage area, either in a storage shed or a storage yard. It must be lifted again to a truck or freight car for transportation to a dealer or contractor. It must be lifted again at the dealer's premises and, yet again, it must be lifted and transported to the site on which it will be permanently installed. The lifting and hauling is obviously not done by the same persons. The manufacturer must have a crew and the dealer, the retailer and the construction company must all have crews of trained men to do this.
More often than not, the actual lifting and positioning of a gate valve or hydrant is accomplished by wrapping and locking a chain around it, attaching the chain to a hoist and then swinging the valve onto a truck or, when it is being installed, into a pre-dug hole or trench. Not only does the wrapping of the chain require skill, but the technique is susceptible to error with the possibility of the valve crashing down where it could injure humans or damage other equipment. Thus, there is a need for simple, dependable lifting mechanisms for this type of apparatus.
One such device called a "Fire Hydrant Setting Tool" is disclosed in U.S. Pat. No. 4,951,989 to Goodin. It has a planar lifting plate which, when assembled on an object to be lifted, must be latched into position and then locked to prevent unlatching.
Another such device called "Tool for Lifting and Installing a Fire Hydrant or the Like" is disclosed in U.S. Pat. No. 3,215,464 to Overman and includes a plurality of hook-like members which are placed over the cap or bonnet of a hydrant and then chained into place.
It is an object of the present invention to provide a lifting tool for such apparatus which is inexpensively made, universal in its operation and can be used by workmen not requiring the particular skill of chain wrapping.
Another object of the invention is to produce a lifting tool which is simple, foolproof and readily used by a person having little or no prior training.